If you insist they give up their culture immediately you will be seen as trying to take away their culture. Just like how gun rights advocates perceive attacks on gun culture.
Solidarity is a normal reaction to real or perceived hostility. In history the social pressure to assimilate resulted in immigrant collectivism in order to support each other; Chinatowns, little Italy and a myriad other ethnic enclaves formed partly because of this pressure.
I don't think there should be any codification of what behavior should be tolerated. Refugees and immigrants entered by legitimate process, they should have the same rights as everyone else: to do whatever they like that's not illegal, believe however they like and even to campaign for change. Equal rights, especially by the law. Anything else creates a secondary class of people with fewer rights.
(Leaving aside that courts have defended human rights of non citizen visitors and illegals.)
Well, I agree my line is pretty much what's legal. I suspect everyone in this thread basically agrees with us on this point. (Of course nations are free to adjust their laws in what some might consider discriminatory ways, as France has done with Burqa bans.) Some like to demonize migrants and hence assume that their 'culture' involves illegal activity - so the manner in which criminal activity is treated is somewhat relevant:
In this regard I'm not so convinced about having exactly the same rights as everyone else. Countries do distinguish between the rights of citizens and the rights of various classes of more temporary residents - second-class citizens exist everywhere. Some European countries seem to be doing more than their fair share when it comes to refugees, and suffering some social stress as a result - if they wish to be less generous in future I think this is understandable. I also think refugees who are lucky enough to be accepted into a foreign country should have some natural obligation not to act against it or its citizens for some period of time. In that sense a serious crime committed by a refugee might not be considered equal to the same crime by a citizen, sadly there are many others who would gladly take that person's privileged place and not similarly burden the host country.
@phoxy (and everyone else), it might be more constructive if you provide specific examples of cultural behaviour on the border of what you think should and shouldn't be tolerated.
There's a spectrum that runs from tasty kebabs to horrific unlawful behaviour. What are two or more examples that illustrate where your line is?